Re: [PATCH][RSDL-mm 0/7] RSDL cpu scheduler for 2.6.21-rc3-mm2 [LWN.net]

From:		Mike Galbraith <efault-AT-gmx.de>
To:		Con Kolivas <kernel-AT-kolivas.org>
Subject:		Re: [PATCH][RSDL-mm 0/7] RSDL cpu scheduler for 2.6.21-rc3-mm2
Date:		Sun, 11 Mar 2007 12:39:09 +0100
Cc:		linux kernel mailing list <linux-kernel-AT-vger.kernel.org>, ck list <ck-AT-vds.kolivas.org>, Andrew Morton <akpm-AT-linux-foundation.org>, Ingo Molnar <mingo-AT-elte.hu>

Hi Con,

On Sun, 2007-03-11 at 14:57 +1100, Con Kolivas wrote:
> What follows this email is a patch series for the latest version of the RSDL 
> cpu scheduler (ie v0.29). I have addressed all bugs that I am able to 
> reproduce in this version so if some people would be kind enough to test if 
> there are any hidden bugs or oops lurking, it would be nice to know in 
> anticipation of putting this back in -mm. Thanks.
> 
> Full patch for 2.6.21-rc3-mm2:
> http://ck.kolivas.org/patches/staircase-deadline/2.6.21-r...

I'm seeing a cpu distribution problem running this on my P4 box.

Scenario:
listening to music collection (mp3) via Amarok.  Enable Amarok
visualization gforce, and size such that X and gforce each use ~50% cpu.
Start rip/encode of new CD with grip/lame encoder.  Lame is set to use
both cpus, at nice 5.  Once the encoders start, they receive
considerable more cpu than nice 0 X/Gforce, taking ~120% and leaving the
remaining 80% for X/Gforce and Amarok (when it updates it's ~12k entry
database) to squabble over.

With 2.6.21-rc3,  X/Gforce maintain their ~50% cpu (remain smooth), and
the encoders (100%cpu bound) get whats left when Amarok isn't eating it.

I plunked the above patch into plain 2.6.21-rc3 and retested to
eliminate other mm tree differences, and it's repeatable.  The nice 5
cpu hogs always receive considerably more that the nice 0 sleepers.

	-Mike